package dblayer;

import java.sql.*;


public class DBConnection
{
	
	
    private static final String driver = "jdbc:sqlserver://balder.ucn.dk:1433";
    private static final String databaseName = ";databaseName=dmaa0913_6a";
    private static String userName = "; user=dmaa0913_6a";
    private static String password = ";password=MaaGodt";
   
  
    private DatabaseMetaData dma;
    private static Connection con;
    
    private static DBConnection instance = null;

    
    private DBConnection()
    {
    	String url = driver + databaseName + userName + password;

        try{
        	
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
            System.out.println("Load af class ok");
          
        }
        catch(Exception e){
            System.out.println("Can not find the driver");
            System.out.println(e.getMessage());
        }
        
        try{
           
            con = DriverManager.getConnection(url);
            con.setAutoCommit(true);
            dma = con.getMetaData(); // get meta data
            System.out.println("Connection to " + dma.getURL());
            System.out.println("Driver " + dma.getDriverName());
            System.out.println("Database product name " + dma.getDatabaseProductName());
        }
        catch(Exception e){

            System.out.println("Problems with the connection to the database");
            System.out.println(e.getMessage());
            System.out.println(url);
        }
    }
    
    public static void closeConnection()
    {
       	try{
            con.close();
            System.out.println("The connection is closed");
       	}
        catch (Exception e){
        	System.out.println("Error trying to close the database " +  e.getMessage());
        }
    }
    
    public  Connection getDBcon()
    {
    	return con;
    }
    
    public static DBConnection getInstance()
    {
        if (instance == null)
        {
          instance = new DBConnection();
        }
        return instance;
    }
    
    public static void startTransaction()
    { 
    	try{
    		con.setAutoCommit(false);
        }
    	catch(Exception e){
    		System.out.println("fejl start transaction");
    		System.out.println(e.getMessage());
      }
    }
    public static void commitTransaction()
    { 
    	try{
    		con.setAutoCommit(true);
        }
    	catch(Exception e){
    		System.out.println("fejl commit transaction");
    		System.out.println(e.getMessage());
    	}
    }
    public static void rollbackTransaction()
    { 
    	try{
    		con.rollback();
    		con.setAutoCommit(true);
        }
    	catch(Exception e){
    		System.out.println("fejl rollback transaction");
    		System.out.println(e.getMessage());
    	}
    }
}
